Rate of Prolonged Response After Stopping Thrombopoietin-receptor Agonists Treatment in ITP

Inclusion Criteria: 1. Age \>= 18 years 2. Diagnosis of ITP according to the standard definition 3. Disease duration of more than 3 months at Tpo-RA initiation 4. Platelet count \> 100 x 109/L for more than 2 months on Tpo-RA Therapy, with at least 3 platelet counts \> 100 x 109/L 5. Blood count lasting for less than 7 days 6. Normal marrow aspirate for patients aged of 60 and over 7. Informed signed consent 8. Treatment with Tpo-RA for at least 3 months Exclusion Criteria: 1\) Anticoagulation or anti-platelet treatment 2) Recent treatment with corticosteroids ± intravenous immunoglobulins (less than 2 months) 3) Rituximab or splenectomy within the 2 months preceding the Tpo-RA initiation 4) Rituximab or splenectomy after Tpo-RA initiation/RA initiation 5) Previous failure of Tpo-RA discontinuation 6) Pregnant or breastfeeding women 7) No affiliation to a social security scheme or other social protection scheme 8) Inability or refusal to understand or refusal to sign the informed consent from study participation 9) Patient deprived of freedom or under legal protection (guardianship, curatorship) 10) Hypersensitivity to Romiplostin or to any of the excipients or to E. coli derived proteins \-